Enhancing the Stability of CH3NH3PbBr3 Nanoparticles Using Double Hydrophobic Shells of SiO2 and Polyvinylidene Fluoride.

Abstract

The instability of lead halide perovskites (LHPs) has tremendously hindered their practical applications. Despite some examples on encapsulating LHPs into a SiO2 shell has been reported, these SiO2-coated LHPs still suffer from limited stability. Herein, MAPbBr3 (MA = CH3NH3+) nanoparticles encapsulated in double hydrophobic shells of organic functionalized SiO2 and polyvinylidene fluoride (MAPbBr3@SiO2/PVDF) are successfully synthesized by infiltrating the MAPbBr3 precursor solution into hollow siliceous nanospheres and followed by PVDF capping. With the dual-protection of SiO2 and PVDF, the MAPbBr3@SiO2/PVDF nanoparticles exhibit drastically improved stability against water and UV-light illumination. A white light-emitting diode with luminous efficiency up to 147.5 lm W-1 and a color gamut encompassing 120% of NTSC in CIE 1931 color space has been demonstrated using the MAPbBr3@SiO2/PVDF nanoparticles as the green light source. This study enlightens new insights in the synthesis of highly stable LHPs-based core/shell/shell architectures toward their practical applications.